M4 Rifle

M4
Rifle

M4 and M4A1 5.56mm Carbine Rifle

M4 Rifle and M4A1 Rifle

The M4 Rifle and the M4A1 5.56mm
Carbine assault rifle are lightweight, gas operated, air
cooled, magazine fed, selective rate, shoulder fired
weapons with a collapsible stocks. A shortened variant of
the M16A2 rifle, the M4 rifle provides the individual
soldier operating in close quarters the capability to
engage targets at extended range with accurate, lethal
fire. The M4 Carbine achieves over 80% commonality with the
M-16A2 Rifle and will replace all M3 .45 caliber submachine
guns and selected M9 pistols and M16 rifle
series.

The M4A1 rifle is a compact lightweight
weapon that is a modified M4 carbine rifle. The M4A1 (SOF
Variant) carbine difrrers from the basic M-4 in the
following features; full automatic firing mode, a flat top
rail for mounting day/night sights (such as the Trijicon
TA01NSN ACOG 4x32 scope and the AN/TVS-5 Crew served weapon
sight) and a detachable carrying handle.

The M4A1 rifle fires the same ammunition as the
M16A2 and the M4 carbine. It also mounts all accessories
common to the M16A2 and M4 to include the 40 mm grenade
launcher. SOF units will have the ability to adapt one
versatile weapon to meet several missions rather than
having many different weapons that are currently
deployed.

The M-4 has interchangeable sighting systems,
add-on vertical forward grips and even a detachable short
version of the M-203 grenade launcher.

The rifle itself is one full pound lighter than
the M-16A2 and 10 inches shorter. The collapsible buttstock
is designed to make it more adaptable to individual
shooters, a benefit especially in tight-packed urban
areas.

There are some drawbacks to the M-4 rifle though.
A shorter barrel means reduced velocity and accuracy at
long ranges.

The M4 rifle is also capable of muzzle launched
ordnance with rubber or rubber encased steel projectile. It
provides a non-lethal means of crowd control up to 30-80
meters.

In the US Marine Corps, M4 rifles were issued to
the provost marshal offices' Special Reactions Teams to
phase out the 9mm Heckler and Koch MP-5. In 1999, the M4
replaced the MP5 in
Marine Force Reconnaissance units, Fleet Anti-Terrorism
Security Teams and Military Police Special Response
Teams.

The Objective Individual Combat Weapon will also
replace M-4 carbines by 2006.

5.56-mm Ammo for the
M-4 223 caliber
M193 ammunition

The 5.56-mm round is the NATO designation for the
.223 caliber bullet. The advantage of the 5.56 round is low
recoil, less weight in ammo compared to the 7.62 NATO,
enables a lighter rifle, and lower cost. However, a big
draw back of the 5.56 round is poor penetration and poor
long-range effectiveness compared to the 7.62
NATO.

The .223 bullet can travel 3,200 feet per second
and it produces minimum recoil. The maximum penetration
occurs at 200 meters. At ranges less then 25 meters,
penetration is greatly reduced. At 10 meters, penetration
by the M4 round is poor, due to the tremendous stress
placed on this high-speed round, which causes it to yaw
upon striking a target. Stress causes the projectile to
break up, and the resulting fragments are often too small
to penetrate.